The present disclosure relates to an optical fiber sensing extension device and an optical fiber sensing system.
Background technology
[0002]
　There is a technology called optical fiber sensing that uses an optical fiber as a sensor. Optical fiber sensing is used to detect the state of the monitored object.
　Here, when the monitored object is an infrastructure such as a road, a railroad track, a utility pole, a tunnel, or a bridge, an existing optical fiber (for example, an existing optical fiber for communication) is laid on the monitored object. Sometimes. In this case, by utilizing the existing optical fiber as a sensor, it is possible to detect the state of the monitored object and the like.
[0003]
　However, in recent years, in optical fiber sensing systems, the objects to be monitored have become diverse, and the existing optical fiber is not always laid near the object to be monitored.
　Further, in order to realize an advanced optical fiber sensing system, higher sensitivity sensing is required, but the detection sensitivity may be insufficient with the existing optical fiber arrangement.
　Therefore, recently, it is required to expand the optical fiber sensing system so that the addition of the monitoring object and the improvement of the detection sensitivity can be realized.
[0004]
　As a technique for expanding the optical fiber sensing system, for example, Patent Document 1 can be mentioned. In the technique described in Patent Document 1, an optical fiber is installed in a monitoring area, and light propagated through the optical fiber is received by a photodiode. Then, the determination detection unit connected to the photodiode via an electric cable detects the vibration or displacement applied to the optical fiber based on the frequency and amplitude of the electric signal detected by the photodiode.
Prior art literature
Patent documents
[0005]
Patent Document 1: Japanese Unexamined Patent Publication No. 2008-309497
Outline of the invention
Problems to be solved by the invention
[0006]
　However, in the technique described in Patent Document 1, it is necessary to newly lay an optical fiber independently of the existing optical fiber. Therefore, there is a problem that the existing optical fiber cannot be effectively used and the new installation cost of the optical fiber becomes expensive.
[0007]
　Therefore, an object of the present disclosure is to provide an optical fiber sensing expansion device and an optical fiber sensing system capable of solving the above-mentioned problems, effectively utilizing the existing optical fiber, and expanding the optical fiber sensing system inexpensively and easily. To provide.
Means to solve problems
[0008]
　The optical fiber sensing expansion device according to one aspect includes
　a sensor unit that stores the optical fiber for sensing,
　a fixed unit that fixes the sensor unit to a monitoring object, and
　a fiber connection unit that can connect the optical fiber for sensing to the optical fiber. The
　fiber connection unit superimposes the detection result of the sensor unit on the optical signal transmitted by the optical fiber.
[0009]
　In the optical fiber sensing system according to one aspect, the
　optical fiber,
　the sensor unit for storing the sensing optical fiber,
　the fixing unit for fixing the sensor unit to the monitoring object, and the
　sensing optical fiber can be connected to the optical fiber. The fiber connection unit includes a fiber connection unit and a
　detection unit, and the
　fiber connection unit superimposes the detection result of the sensor unit on the optical signal transmitted by the optical fiber, and the
　detection unit is superimposed on the optical signal. Based on the detection result of the sensor unit, the pattern corresponding to the monitored object is detected.
The invention's effect
[0010]
　According to the above aspect, it is possible to obtain an effect that the optical fiber sensing system can be expanded inexpensively and easily by effectively utilizing the existing optical fiber.
A brief description of the drawing
[0011]
FIG. 1 is a diagram showing an example of a basic configuration of an optical fiber sensing system according to an embodiment.
FIG. 2 is a diagram showing an example of a monitoring point of a monitoring object in which a sensor unit according to an embodiment is installed.
[Fig. 3] Fig. 3 is a diagram showing an example of a unique pattern according to a monitored object.
[Fig. 4] Fig. 4 is a diagram showing another example of a unique pattern according to a monitored object.
FIG. 5 is a diagram showing an example of a connection method in which the fiber connection portion according to the embodiment connects the sensing optical fiber to the optical fiber.
FIG. 6 is a diagram showing another example of a connection method in which the fiber connection portion according to the embodiment connects the sensing optical fiber to the optical fiber.
FIG. 7 is a diagram showing an example of a path in which the fiber connection portion according to the embodiment transmits the detection result of the parameter in the monitored object.
FIG. 8 is a diagram showing another example of a path in which the fiber connection portion according to the embodiment transmits the detection result of the parameter in the monitored object.
FIG. 9 is a diagram showing an example of a configuration that is a modification of the optical fiber sensing system according to the embodiment.
FIG. 10 is a diagram showing another example of a configuration that is a modification of the optical fiber sensing system according to the embodiment.
FIG. 11 is a diagram showing an example of a configuration of a fiber connection portion according to an embodiment.
FIG. 12 is a diagram showing an example of an arrangement pattern of a sensing optical fiber in a sensor unit according to an embodiment.
FIG. 13 is a diagram showing another example of the arrangement pattern of the sensing optical fiber in the sensor unit according to the embodiment.
FIG. 14 is a diagram showing still another example of the arrangement pattern of the sensing optical fiber in the sensor unit according to the embodiment.
FIG. 15 is a diagram showing an example of a three-dimensional arrangement of sensing optical fibers in the sensor unit according to the embodiment.
FIG. 16 is a diagram showing an example of a state in which a cushioning material is sandwiched between the sensing optical fiber and the monitored object according to the embodiment.
FIG. 17 is a diagram showing an example of a configuration in which an optical fiber is accompanied by a branched configuration in the optical fiber sensing system according to the present embodiment.
FIG. 18 is a diagram showing another example of the configuration when the optical fiber is accompanied by a branched configuration in the optical fiber sensing system according to the present embodiment.
FIG. 19 is a flow chart showing an example of an operation flow of the optical fiber sensing system according to the present embodiment.
FIG. 20 is a diagram showing an example of a configuration of a fiber connection portion according to another embodiment.
FIG. 21 is a diagram showing another example of the configuration of the fiber connection portion according to another embodiment.
FIG. 22 is a diagram showing an example of a basic configuration of an optical fiber sensing system according to another embodiment.
Mode for carrying out the invention
[0012]
　Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

　First, the basic configuration of the optical fiber sensing system according to the present embodiment will be described with reference to FIG.
[0013]
　As shown in FIG. 1, the optical fiber sensing system according to the present embodiment includes an optical fiber 10, an optical fiber sensing device 20, and an optical fiber sensing expansion device 30. The optical fiber sensing device 20 is an example of a detection unit.
[0014]
　The optical fiber 10 is an existing optical fiber extending from the optical fiber sensing device 20 and laid in infrastructure such as roads, lines, utility poles, tunnels, and bridges. The optical fiber 10 may be a communication optical fiber or a sensing optical fiber laid in advance for monitoring the above-mentioned infrastructure. Further, in general, the communication optical fiber is laid in the form of an optical fiber cable coated with a plurality of communication optical fibers. At this time, if there is an unused communication optical fiber among the plurality of communication optical fibers, the unused communication optical fiber may be used as the optical fiber 10.
[0015]
　The optical fiber sensing expansion device 30 includes a sensor unit 32 in which the sensing optical fiber 33 is housed, and a fiber connecting unit 31 capable of connecting the sensing optical fiber 33 to the optical fiber 10. The optical fiber sensing expansion device 30 also includes a fixing portion for fixing the sensor unit 32 to the monitoring object 40 (see FIG. 2 and the like), and the details of the fixing portion will be described later.
[0016]
　In the optical fiber sensing system according to the present embodiment, when the monitoring object 40 is added or the detection sensitivity is improved, the sensor unit 32 is added to the monitoring object 40 to be added or the monitoring object 40 to increase the detection sensitivity. Is installed. The monitored object 40 is, for example, infrastructure such as roads, railroad tracks, utility poles, tunnels, bridges, and the periphery of those infrastructures. The sensor unit 32 is fixed to the monitoring target object 40 itself, or is buried and fixed in the ground near the monitoring target object 40. Further, since the monitoring target object 40 has different vibrations and the like at each position, the sensor units 32 may be installed at a plurality of monitoring points for one monitoring target object 40. FIG. 2 shows an example in which the sensor unit 32 is installed at two monitoring points P1 and P2 of the tunnel when the monitored object 40 is a tunnel. Further, the sensor unit 32 may be installed in the monitoring target object 40 by accommodating the optical fiber sensing expansion device 30 in the housing and installing the housing itself in the monitoring target object 40.
[0017]
　As described above, the sensor unit 32 stores the sensing optical fiber 33. The storage method of the sensing optical fiber 33 is not particularly limited. For example, the sensor unit 32 may be used as a housing, and the sensing optical fiber 33 may be housed inside the housing, or the sensor unit 32 may be composed of a member having a predetermined shape (for example, a rectangular parallelepiped shape) and the outer surface of the member. The sensing optical fiber 33 may be attached to the surface with a tape or the like. Further, the length of the sensing optical fiber 33 may be a length corresponding to the monitored object 40 in which the sensor unit 32 is installed. For example, the length of the sensing optical fiber 33 may be about 1 m if the monitored object 40 is a utility pole and about 10 m if the monitored object 40 is a tunnel, but the length is not limited to this. .. Then, the sensor unit 32 detects various parameters such as vibration, sound, temperature, and stress generated in the monitored object 40 in which the sensor unit 32 is installed by using the sensing optical fiber 33.
[0018]
　As described above, the fiber connection portion 31 has a configuration in which the sensing optical fiber 33 can be connected to the optical fiber 10. The fiber connection portion 31 is configured so that the sensing optical fiber 33 can be connected not only to the existing optical fiber such as the optical fiber 10 but also to the newly installed optical fiber. Then, the fiber connection unit 31 superimposes the detection result of the parameter on the monitored object 40 detected by the sensor unit 32 on the optical signal transmitted by the optical fiber 10.
[0019]
　The optical fiber sensing device 20 incidents an optical signal on the optical fiber 10 and receives an optical signal from the optical fiber 10. For example, the optical signal incident on the optical fiber 10 is pulsed light serving as a detection optical signal, and the optical signal received from the optical fiber 10 is associated with the transmission of this pulsed light through the optical fiber 10. It is scattered light generated for each transmission distance.
[0020]
　Here, as described above, the detection results of the parameters (vibration, sound, temperature, stress, etc.) of the monitored object 40 detected by the sensor unit 32 are superimposed on the optical signal received by the optical fiber sensing device 20. ing. At this time, the pattern of each parameter in the monitored object 40 is a dynamically fluctuating fluctuation pattern, which differs depending on the state, structure, material, and the like of the monitored object 40. For example, when the parameter is vibration, it is possible to define a dynamic unique pattern of vibration generated in the monitored object 40 by detecting the strength of the vibration, the vibration position, the transition of the fluctuation of the frequency, and the like. It becomes.
[0021]
　Therefore, the optical fiber sensing device 20 uses, for example, a distributed vibration sensor (Distributed Vibration Sensor) based on the detection result of vibration in the monitored object 40, and dynamically unique patterns of vibration in the monitored object 40. Is detected. 3 and 4 are examples of dynamic specific patterns of vibration when the monitored object 40 is a structure such as a tunnel, and vibration data of the structure (horizontal axis is time, vertical axis is intensity (amplitude). )) Shows the frequency characteristics (frequency on the horizontal axis and intensity (amplitude) on the vertical axis) after FFT (Fast Fourier Transform). As shown in FIGS. 3 and 4, an intensity peak occurs in the frequency characteristics of the structure, and the frequency at which this peak occurs differs depending on the deterioration state of the structure. Therefore, the optical fiber sensing device 20 can determine the deterioration state of the structure by detecting the dynamic unique pattern of the vibration of the structure.
[0022]
　Further, the optical fiber sensing device 20 uses a distributed acoustic sensor, a distributed temperature sensor, or the like, and also includes a dynamic unique pattern such as sound and temperature in the monitored object 40. By detecting, the complex unique pattern of the monitored object 40 may be detected. As a result, the state, structure, material, etc. of the monitored object 40 can be determined with higher accuracy.
[0023]
　Further, the optical fiber sensing device 20 identifies the position where the unique pattern is generated, for example, based on the time difference between the time when the pulsed light is incident on the optical fiber 10 and the time when the scattered light is received from the optical fiber 10. You can also do it. Thereby, the optical fiber sensing device 20 can also specify the position of the monitored object 40.
[0024]
　As described above, in the optical fiber sensing expansion device 30 according to the present embodiment, the sensor unit 32 in which the sensing optical fiber 33 is stored and the sensing optical fiber 33 can be connected to the optical fiber 10, and the sensor unit 32 can connect the sensor unit 32. It includes a fiber connecting portion 31 that superimposes the detected detection result on an optical signal transmitted by the optical fiber 10, a fixing portion that fixes the sensor unit 32 to the monitored object 40, and the like.
[0025]
　Therefore, the sensor unit 32 is fixed to the monitoring object 40 to be added, the monitoring object 40 to increase the detection sensitivity, and the like, and the sensing optical fiber 33 is connected to the existing optical fiber 10 by the fiber connection unit 31 for monitoring. It is possible to add an object 40 and expand the detection sensitivity. Therefore, the existing optical fiber 10 can be effectively utilized to expand the optical fiber sensing system inexpensively and easily.
　Hereinafter, the optical fiber sensing system according to the present embodiment will be described in more detail.
[0026]

　First, a connecting method of connecting the sensing optical fiber 33 to the optical fiber 10 in the fiber connecting portion 31 will be described.
(A1) Optical connection The
　fiber connection portion 31 may optically connect the sensing optical fiber 33 to the optical fiber 10.
　For example, as shown in FIG. 5, the fiber connection portion 31 may directly connect the wire of the sensing optical fiber 33 to the wire of the optical fiber 10. A splice or the like may be used for the connection in this case.
　Alternatively, as shown in FIG. 6, the fiber connection portion 31 may connect the wire of the sensing optical fiber 33 to the wire of the optical fiber 10 by using the connector CN. In FIG. 6, the connector CN is arranged on the optical fiber 10 side and the optical fiber sensing expansion device 30 side, but the arrangement of the connector CN is not limited to this. For example, the connector CN may be arranged only on the optical fiber 10 side, may be arranged only on the optical fiber sensing expansion device 30 side, or may be arranged only between the optical fiber 10 and the optical fiber sensing expansion device 30. It may be arranged.
[0027]
　Here, when the fiber connection portion 31 optically connects the sensing optical fiber 33 to the optical fiber 10, the detection optical signal (pulse) in which the optical fiber sensing device 20 is incident on the optical fiber 10 is connected to the fiber connection portion 31. Light) is received. Specifically, on the optical fiber 10, an optical coupler or an optical splitter (not shown) is provided in front of the connection portion with the fiber connection portion 31, and the detection light demultiplexed by the optical coupler or the optical splitter is provided. The signal is received. Therefore, the sensing optical fiber 33 stored in the sensor unit 32 generates scattered light with respect to the detection optical signal. This scattered light fluctuates according to vibration, sound, temperature, stress, etc. generated in the monitored object 40 in which the sensor unit 32 is installed. Therefore, the sensor unit 32 detects various parameters such as vibration, sound, temperature, and stress in the monitored object 40 by detecting the scattered light.
[0028]
　At this time, several routes can be considered as the route for the fiber connection unit 31 to transmit the detection result of the parameter in the monitored object 40 detected by the sensor unit 32.
　For example, as shown in FIG. 7, the fiber connection unit 31 may transmit the detection result in the direction opposite to the transmission direction of the detection optical signal (that is, the direction of the optical fiber sensing device 20).
　Alternatively, as shown in FIG. 8, the fiber connection portion 31 may transmit the detection result in the same direction as the transmission direction of the detection optical signal (that is, in the direction opposite to the direction of the optical fiber sensing device 20). .. However, in the case of FIG. 8, the optical fiber sensing device 20 cannot receive the detection result as it is. Therefore, for example, as shown in FIG. 9, the optical fiber 10 may be looped and both ends of the optical fiber 10 may be connected to the optical fiber sensing device 20. Alternatively, as shown in FIG. 10, one end of the optical fiber 10 may be connected to the optical fiber sensing device 20 and the other end may be connected to another optical fiber sensing device 20A. In the case of FIG. 10, the optical fiber sensing device 20 incidents a detection optical signal on the optical fiber 10, the optical fiber sensing device 20A receives the detection result from the optical fiber 10, and the monitored object is monitored based on the detection result. Forty unique patterns will be detected.
[0029]
(A2) The connection
　fiber connection portion 31 other than the optical connection may connect the sensing optical fiber 33 to the optical fiber 10 by a method other than the optical connection. Here, the fiber connection unit 31 detects the unique pattern of the monitored object 40 based on the detection result of the parameter in the monitored object 40 detected by the sensor unit 32, and uses the detected unique pattern as the optical fiber 10. It shall be superimposed on the optical signal transmitted by. Hereinafter, the configuration of the fiber connection portion 31 in this case will be described with reference to FIG.
[0030]
　The fiber connection unit 31 shown in FIG. 11 includes a light source 311, a detection optical signal output unit 312, a pattern detection unit 313, and a disturbance generation unit 314.
　In the case of the configuration of FIG. 11, since the fiber connection portion 31 does not optically connect the sensing optical fiber 33 to the optical fiber 10, the detection optical signal (pulse light) in which the optical fiber sensing device 20 is incident on the optical fiber 10 Is not received. Therefore, the light source 311 is provided to generate a detection optical signal incident on the sensing optical fiber 33.
　The detection optical signal output unit 312 generates a detection optical signal from the output of the light source 311 and incidents the generated detection optical signal on the sensing optical fiber 33 stored in the sensor unit 32.
[0031]
　The pattern detection unit 313 detects and detects a dynamic unique pattern according to the state, structure, material, etc. of the monitoring object 40 based on the detection result of the parameter in the monitoring object 40 detected by the sensor unit 32. The disturbance generation unit 314 is controlled based on the generated pattern. The method for detecting the unique pattern may be the same as the method for detecting the unique pattern in the optical fiber sensing device 20 described above.
[0032]
　Under the control of the pattern detection unit 313, the disturbance generation unit 314 superimposes the unique pattern of the monitoring object 40 detected by the pattern detection unit 313 on the optical signal transmitted by the optical fiber 10. Specifically, the disturbance generation unit 314 gives the optical fiber 10 a disturbance corresponding to the unique pattern of the monitored object 40, thereby converting the unique pattern of the monitored object 40 into an optical signal transmitted through the optical fiber 10. Superimpose. The disturbance applied to the optical fiber 10 is, for example, vibration, sound, heat, or the like. For example, the disturbance generation unit 314 gives the optical fiber 10 a vibration source that gives the optical fiber 10 vibration according to the vibration pattern generated by the monitored object 40, and a sound corresponding to the acoustic pattern generated by the monitored object 40 to the optical fiber 10. A sound source (for example, a speaker, a hammer, etc.), a heat source that gives the optical fiber 10 a temperature change according to a temperature pattern generated in the monitored object 40, or the like. Further, the disturbance generation unit 314 may give the optical fiber 10 a disturbance according to the unique pattern of the monitored object 40, that is, a disturbance corresponding to the state of the monitored object 40 or the like. Therefore, the disturbance generation unit 314 may give the optical fiber 10 a disturbance by using a source different from the source that detected the state of the monitored object 40 or the like. For example, when the state of the monitored object 40 or the like is detected by vibration, the disturbance according to the natural pattern of sound or temperature generated in the monitored object 40 in that state or the like is emitted by light using a sound source or a heat source. It may be given to the fiber 10.
[0033]

　Subsequently, an installation method for installing the sensor unit 32 on the monitoring object 40 will be described.
(B1) Method Using a Housing The
　sensor unit 32 may be housed in the housing together with the fiber connecting portion 31, and the housing itself may be fixed to the monitoring object 40. At this time, as a fixing method for fixing the housing to the monitoring target object 40, a method such as placing the housing on the monitoring target object 40 or attaching the housing to the monitoring target object 40 with tape or the like may be used. If the monitored object 40 is a structure, the fixing method includes driving the housing into the monitored object 40 with a bolt or the like, winding the housing around the monitored object 40 with a string or the like, and fixing the housing with a fixing jig. It may be fixed to the monitoring object 40 by using.
[0034]
(B2) Method without using a housing The
　sensing optical fiber 33 stored in the sensor unit 32 may be fixed to the monitored object 40 with tape. At this time, the sensing optical fiber 33 and the tape may be integrated in advance. Further, a sheet (for example, a resin sheet) having a built-in sensing optical fiber 33 stored in the sensor unit 32 may be fixed to the monitoring object 40. Further, in the case of the method (B2), the fiber connection portion 31 may be housed in a housing, and the housing may be fixed to the monitoring object 40 by the method (B1) described above.
[0035]
　That is, in the above-mentioned fixing portion (fixing portion for fixing the sensor unit 32 to the monitoring object 40), in the method (B1) described above, for example, the housing for accommodating the sensor unit 32 is fixed to the monitoring object 40. It can be tapes, bolts, strings, fixing jigs, etc. Further, in the above-mentioned method (B2), the above-mentioned fixing portion becomes, for example, a tape, a sheet, or the like for fixing the sensing optical fiber 33 stored in the sensor portion 32 to the monitoring object 40.
[0036]
Next, an arrangement pattern of the sensing optical fiber 33 in the sensor unit 32 will be described.
　The arrangement pattern of the sensing optical fiber 33 in the sensor unit 32 may be various patterns. For example, the sensing optical fiber 33 may have a linear pattern as shown in FIG. 12, a folded pattern as shown in FIG. 13, or a spiral as shown in FIG. It may be a structural pattern. Of these, the patterns of the folded structure and the spiral structure shown in FIGS. 13 and 14 improve the density of the sensing optical fiber 33, so that the detection sensitivity of the monitored object 40 can be improved.
[0037]
　Further, as shown in FIG. 15, the sensing optical fiber 33 may be three-dimensionally arranged in each of the three axial directions orthogonal to each other in the sensor unit 32. Specifically, for example, when the sensor unit 32 has a rectangular parallelepiped shape, the sensing optical fiber 33 having the pattern of any one of FIGS. 12 to 14 is parallel to, for example, the front side surface 32a and the YZ plane which are changed to the XZ plane. It may be arranged on the right side surface 32b and the upper surface 32c parallel to the XY plane. This makes it possible to detect the vibration status of three different vibration axes of the monitored object 40.
[0038]
　Further, for example, in a situation where the monitored object 40 violently shakes, if the sensing optical fiber 33 is directly installed on the monitored object 40, excessive vibration is detected, and the vibration state is detected with an appropriate intensity. Can not be done.
　Therefore, as shown in FIG. 16, the sensing optical fiber 33 is monitored with the sensing optical fiber 33 sandwiched between the sensing optical fiber 33 and the monitoring object 40 with a cushioning material 34 for cushioning an impact such as a cushion. It may be installed in. As a result, the intensity of vibration detected by the sensor unit 32 can be adjusted, and the detection sensitivity can be adjusted.
[0039]

　Next , the arrangement position of the optical fiber sensing device 20 will be described.
　The optical fiber sensing device 20 may be arranged inside the communication carrier station building or may be arranged outside the communication carrier station building.
　Further, when the optical fiber sensing device 20 is arranged outside the communication carrier station building, the optical fiber sensing device 20 may be arranged near the optical fiber sensing expansion device 30. Further, a plurality of optical fiber sensing devices 20 may be arranged. For example, one optical fiber sensing device 20 may be arranged for a predetermined number (for example, 10) of the optical fiber sensing expansion devices 30. Further, in the region where a plurality of optical fiber sensing expansion devices 30 are arranged, one optical fiber sensing device 20 may be arranged for a predetermined distance (for example, 10 m).
[0040]

　Next, in the optical fiber sensing system according to the present embodiment, a configuration when the optical fiber 10 has a branched configuration will be described.
　For example, in a subscriber-side optical communication network using an optical fiber 10 laid on a utility pole, a 1: N-type communication method is used between the communication carrier station building side and the subscriber side, as in PON (Passive Optical Network). Is adopted.
　As shown in FIG. 17, when the 1: N type communication method is adopted in the optical fiber sensing system according to the present embodiment, one branch portion 50 such as an optical coupler or a WSS (Wavelength Selectable Switch) is provided. The above (two in FIG. 17) are installed, and the optical fiber 10 is branched by the branch portion 50.
[0041]
　At this time, the optical fiber sensing expansion device 30 may be arranged so as to terminate the line of the unused optical fiber 10 after branching (optical fiber sensing expansion device 30A in FIG. 17). Alternatively, the optical fiber sensing expansion device 30 may be arranged so as to be inserted in the middle of the line of the optical fiber 10 in use after branching as in FIG. 1 (optical fiber sensing expansion device 30B in FIG. 17). ..
[0042]
　Here, it is assumed that the same wavelength is used in each line of the optical fiber 10 after branching, and there is an optical fiber sensing extension device 30 located at the same distance from the optical fiber sensing device 20 in each of the two different lines. .. However, in this case, even if the optical fiber sensing device 20 receives scattered light from two optical fiber sensing expansion devices 30 located on two different lines, the two optical fiber sensing expansion devices 30 can be distinguished from each other. Can not.
[0043]
　Therefore, different wavelengths may be assigned to each line after branching so that the optical fiber sensing device 20 can identify the different lines according to the wavelength of the optical signal. In the example of FIG. 17, the wavelength λ 1 is assigned to the line on which the optical fiber sensing expansion device 30A is arranged . Therefore, the fiber connection 31 of the optical fiber sensing expansion device 30A, the wavelength lambda 1 having a filter 315 for passing the optical signal of the wavelength lambda between the line 1 is configured to transmit and receive only an optical signal of There is. Further, a wavelength λ n is assigned to the line on which the optical fiber sensing expansion device 30B is arranged . Therefore, the fiber connection 31 of the optical fiber sensing expansion device 30B, the wavelength lambda n includes a filter 315 for passing an optical signal of a wavelength lambda between the line n and is configured to transmit and receive only an optical signal of There is.
[0044]
　Further, as shown in FIG. 18, the wavelength may be assigned not for each line but for each optical fiber sensing extension device 30. At this time, it is preferable that the optical fiber sensing extension devices 30 located on different lines but at the same distance from the optical fiber sensing device 20 are assigned wavelengths so that the wavelengths are different from each other. As a result, the optical fiber sensing device 20 can identify the optical fiber sensing extension device 30 by the wavelength of the optical signal.
[0045]
　In the example of FIG. 18, the optical fiber sensing expansion devices 30A and 30B are located on different lines, but at the same distance from the optical fiber sensing device 20. Therefore, the optical fiber sensing expansion device 30A wavelength lambda 1 is assigned, the wavelength lambda is the optical fiber sensing expansion device 30B 2 are allocated. The optical fiber sensing extension devices 30C and 30D are also located on different lines, but at the same distance from the optical fiber sensing device 20. Therefore, the optical fiber sensing expansion device 30C wavelength lambda 2 are assigned, the wavelength lambda is the optical fiber sensing expansion unit 30D 3 is assigned. Further, in the example of FIG. 18, the wavelength λ 2 is assigned to both the optical fiber sensing expansion devices 30B and 30C . This is because the optical fiber sensing expansion devices 30B and 30C have different distances from the optical fiber sensing device 20, so that the optical fiber sensing device 20 can distinguish between them by the distance, and both can be distinguished by the wavelength of the optical signal. This is because there is no need to identify it.
[0046]
　Therefore, the fiber connection 31 of the optical fiber sensing expansion device 30A, the wavelength lambda 1 having a filter 315 for passing the optical signal of the wavelength lambda 1 is configured to transmit and receive only an optical signal of. Similarly, optical fiber sensing expansion device 30B, fiber connection portion 31 of 30C, the wavelength lambda 2 includes a filter 315 for passing an optical signal of the wavelength lambda 2 is configured to transmit and receive only an optical signal of the optical fiber sensing fiber connecting portion 31 of the expansion device 30D, the wavelength lambda 3 includes a filter 315 for passing an optical signal of the wavelength lambda 3 is configured to transmit and receive only an optical signal of.
[0047]
　The wavelength allocation for each optical fiber sensing expansion device 30 shown in FIG. 18 is an example, and is not limited thereto. The wavelength may be assigned by any method that allows the optical fiber sensing device 20 to identify each of the plurality of optical fiber sensing extension devices 30.
[0048]

　Hereinafter, the operation of the optical fiber sensing system according to the present embodiment will be described. Here, the operation flow of the optical fiber sensing system according to the present embodiment will be described with reference to FIG. In FIG. 19, the sensor unit 32 of the optical fiber sensing expansion device 30 is installed in the monitored object 40, and the sensing optical fiber 33 stored in the sensor unit 32 is connected to the optical fiber 10 by the fiber connection unit 31. It shows the later operation.
[0049]
　As shown in FIG. 19, first, the sensor unit 32 detects various parameters such as vibration, sound, temperature, and stress generated in the monitored object 40 by using the sensing optical fiber 33 (step S1). ).
　Subsequently, the fiber connection unit 31 superimposes the detection result of the parameter on the monitored object 40 detected by the sensor unit 32 on the optical signal transmitted by the optical fiber 10 (step S2).
　After that, the optical fiber sensing device 20 receives an optical signal on which the detection result of the parameter in the monitoring object 40 is superimposed, and based on the detection result of the parameter in the monitoring object 40, creates a pattern according to the monitoring object 40. Detect (step S3). This pattern is a dynamic unique pattern according to the state, structure, material, etc. of the monitored object 40.
[0050]

　As described above, according to the present embodiment, the optical fiber sensing expansion device 30 uses the sensor unit 32 in which the sensing optical fiber 33 is housed and the sensing optical fiber 33 in the optical fiber 10. It is possible to connect, and includes a fiber connection unit 31 that superimposes the detection result detected by the sensor unit 32 on the optical signal transmitted through the optical fiber 10, a fixing unit that fixes the sensor unit 32 to the monitoring object 40, and the like. ing.
[0051]
　Therefore, the sensor unit 32 is fixed to the monitoring object 40 to be added, the monitoring object 40 to increase the detection sensitivity, and the like, and the sensing optical fiber 33 is connected to the existing optical fiber 10 by the fiber connection unit 31 for monitoring. It is possible to add an object 40 and expand the detection sensitivity. Therefore, the existing optical fiber 10 can be effectively utilized to expand the optical fiber sensing system inexpensively and easily.
[0052]
　Further, according to the present embodiment, an optical fiber sensing technique using an optical fiber as a sensor is used. Therefore, advantages such as being unaffected by electromagnetic noise, eliminating the need for power supply to the sensor, being excellent in environmental resistance, and facilitating maintenance can be obtained.
[0053]
In
　the example of FIG. 11, the fiber optical fiber connection portion 31 detects a dynamic unique pattern according to the state, structure, material, etc. of the monitored object 40, and sets the unique pattern of the monitored object 40. Although the corresponding disturbance is given to the optical fiber 10, the unique pattern of the monitored object 40 may be directly transmitted to the optical fiber sensing device 20. Hereinafter, the configuration of the fiber connection portion 31 in this case will be described with reference to FIG. 20.
[0054]
　The fiber connection unit 31 shown in FIG. 20 is different from the configuration shown in FIG. 11 in that the disturbance generation unit 314 is replaced with the wireless transmission unit 316.
　The wireless transmission unit 316 wirelessly transmits the unique pattern of the monitoring object 40 detected by the pattern detection unit 313 to the optical fiber sensing device 20. Therefore, the monitoring section of the optical fiber sensing device 20 is shortened, and the number of monitored objects 40 to be monitored is reduced. Since the monitoring section of the optical fiber sensing device 20 is short, the transmission distance of the pulsed light and the scattered light is shortened, so that the fiber loss is reduced. As a result, the S / N ratio (signal-to-noise ratio) of the received scattered light can be improved, and the monitor accuracy can be improved. Further, the monitoring cycle can be improved by reducing the number of monitored objects 40 to be monitored by the optical fiber sensing device 20.
[0055]
　In the example of FIG. 20, the detection optical signal output unit 312 incidents the detection optical signal generated from the output of the light source 311 on the sensing optical fiber 33, but the present invention is not limited to this. For example, as shown in FIG. 21, the sensing optical fiber 33 is optically connected to the optical fiber 10, and the detection optical signal received from the optical fiber sensing device 20 is incident on the sensing optical fiber 33. Is also good.
[0056]
　Further, in the examples of FIGS. 20 and 21, the unique pattern of the monitored object 40 is transmitted wirelessly, but the transmission of the unique pattern is not limited to wireless transmission. For example, a wired transmission unit may be provided instead of the wireless transmission unit 316, and the wired transmission unit may transmit a unique pattern by wire via a LAN (Local Area Network) cable or the like.
[0057]
　Further, as shown in FIG. 22, the optical fiber sensing system of the monitoring object 40 is based on a unique pattern according to the state, structure, material, etc. of the monitoring object 40 detected by the optical fiber sensing device 20. An analyzer 60 for analyzing a state, a structure, a material, and the like may be provided. For example, the analyzer 60 performs pattern analysis of a unique pattern (for example, transition of change in vibration intensity) that dynamically represents a change in vibration according to the state, structure, material, etc. of the monitored object 40. The state, structure, material, etc. of the monitored object 40 can be detected with high accuracy. The analyzer 60 may be arranged inside the communication carrier station building together with the optical fiber sensing device 20, or may be arranged outside the communication carrier station building.
[0058]
　Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various changes that can be understood by those skilled in the art can be made to the structure and details of the present disclosure within the scope of the present disclosure.
[0059]
　For example, in the present disclosure, a computer program in which a processor such as a CPU (Central Processing Unit) stores arbitrary processing of an optical fiber sensing expansion device in a memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory). It is also possible to realize by reading and executing.
[0060]
　The programs described above can be stored and supplied to a computer using various types of non-transitory computer readable medium. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-temporary computer-readable media include magnetic recording media (eg flexible discs, magnetic tapes, hard disk drives), opto-magnetic recording media (eg optomagnetic discs), CD-ROMs (Compact Disc-Read Only Memory), CDs. -R (CD-Recordable), CD-R / W (CD-ReWritable), semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)) include. The programs described above may also be supplied to the computer by various types of transient computer readable media. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.
[0061]
　In addition, some or all of the above embodiments may be described as in the following appendix, but are not limited to the following.
　　　(Supplementary Note 1)
　and a sensor unit for storing the sensing optical fiber,
　and a fixing unit for fixing the sensor unit to the object to be monitored,
　and a fiber connection part connectable to an optical fiber sensing optical fiber,
　wherein The fiber connection unit is an
　optical fiber sensing extension device that superimposes the detection result of the sensor unit on the optical signal transmitted by the optical fiber.
　　　(Appendix 2) 　The optical fiber sensing expansion device according to Appendix 1,
　wherein the optical fiber is an existing optical fiber
.
　　　(Supplementary Note 3) The
　above-
　described Appendix 1 or 2, wherein the fiber connection portion detects a pattern corresponding to the monitored object based on the detection result of the sensor unit, and superimposes the detected pattern on the optical signal . Optical fiber sensing extension device.
　　　(Appendix 4) 　The optical fiber sensing expansion device
　according to
Appendix 3, wherein the fiber connection portion applies disturbance to the optical fiber according to the detected pattern .
　　　(Appendix 5) The
　fixing portion fixes the housing including the sensor portion to the monitored object.
　The optical fiber sensing extension device according to any one of Appendix 1 to 4.
　　　(Supplementary note 6) 　The optical fiber sensing expansion device according to any one of Supplementary note 1 to 5,
　wherein the sensing optical fiber is arranged in each of the three axial directions orthogonal to each other in the sensor unit
.
　　　(Appendix 7) The
　fixing portion is
　any one of Appendix 1 to 6 , wherein the sensor portion is fixed to the monitoring object with a cushioning material sandwiched between the sensing optical fiber and the monitoring object. The optical fiber sensing extension device according to item 1.
　　　(Supplementary Note 8) The
　optical fiber is branched by a branching portion, and the
　fiber connecting portion connects the sensing optical fiber to the optical fiber line branched by the branching portion
　. The optical fiber sensing extension device according to any one item.
　　　(Appendix 9) A
　wavelength is assigned to each line of the optical fiber, and the
　fiber connection portion is a filter that passes an optical signal having a wavelength assigned to the line of the optical fiber to which the optical fiber for sensing is connected.
　8. The optical fiber sensing extension device according to Appendix 8, which transmits and receives an optical signal of the wavelength to and from the line .
　　　(Appendix 10)
　A wavelength is assigned to the optical fiber sensing expansion device, and the
　fiber connection portion includes a filter for passing an optical signal having a wavelength assigned to the optical fiber sensing expansion device, and connects the sensing optical fiber.
　The optical fiber sensing extension device according to Appendix 8, which transmits and receives an optical signal of the wavelength to and from the optical fiber line .
　　　(Appendix 11) An
　optical fiber,
　a sensor unit for storing the sensing optical fiber,
　a fixing unit for fixing the sensor unit to a monitoring object, and
　a fiber connecting unit capable of connecting the sensing optical fiber to the optical fiber. ,
　And the
　fiber connection unit superimposes the detection result of the sensor unit on the optical signal transmitted by the optical fiber, and the
　detection unit superimposes the detection result of the sensor unit superimposed on the optical signal. An
　optical fiber sensing system that detects a pattern according to the monitored object based on the detection result .
　　　(Appendix 12) 　The optical fiber sensing system according to Appendix 11,
　wherein the optical fiber is an existing optical fiber
.
　　　(Appendix 13)

　The optical fiber sensing system according to Appendix 11 or 12, 　wherein the fiber connection unit detects a pattern corresponding to the monitored object based on the detection result of the sensor unit, and superimposes the detected pattern on the optical signal. ..
　　　(Appendix 14) 　The optical fiber sensing system
　according to
Appendix 13, wherein the fiber connection portion applies disturbance to the optical fiber according to the detected pattern .
　　　(Supplementary Note 15) 　The optical fiber sensing system according to any one of Supplementary note 11 to 14,
　wherein the fixing portion fixes a housing including the sensor portion to the monitored object
.
　　　(Supplementary note 16) 　The optical fiber sensing system according to any one of Supplementary note 11 to 15,
　wherein the sensing optical fiber is arranged in each of the three axial directions orthogonal to each other in the sensor unit
.
　　　(Appendix 17)
　A cushioning material sandwiched between the sensing optical fiber and the monitored object is further provided, and the
　fixing portion sandwiches the cushioning material between the sensing optical fiber and the monitored object.
　The optical fiber sensing system according to any one of Appendix 11 to 16 , wherein the sensor unit is fixed to the monitored object in this state .
　　　(Appendix 18)
　Further comprising a branching unit for branching the optical fiber,
　said fiber connecting portion, the connecting the sensing optical fiber line of said optical fiber which is branched by the branching unit,
　in any one of Supplementary Note 11 17 The fiber optic sensing system described.
　　　(Appendix 19) A
　wavelength is assigned to each line of the optical fiber, and the
　fiber connection portion is a filter that passes an optical signal having a wavelength assigned to the line of the optical fiber to which the optical fiber for sensing is connected.
　18. The optical fiber sensing system according to Appendix 18 , wherein an optical signal of the wavelength is transmitted to and received from the line .
　　　(Appendix 20) A
　plurality of optical fiber sensing expansion devices including the sensor unit, the fixing unit, and the fiber connection unit are provided,
　and a wavelength is assigned to each optical fiber sensing expansion device
　. a filter for passing the self-light signal of the wavelength assigned to the optical fiber sensing expansion unit, for transmitting and receiving optical signals wavelength between lines of the optical fiber connected to the sensing optical fiber,
　Appendix 18. The optical fiber sensing system according to 18.
[0062]
　This application claims priority on the basis of Japanese application Japanese Patent Application No. 2018-225998 filed on November 30, 2018, and incorporates all of its disclosures herein.
Code description
[0063]
　10 Optical fiber (existing) 20,
　20A Optical fiber sensing device
　30, 30A, 30B, 30C, 30D Optical fiber sensing extension device
　31 Fiber connection unit
　311 Light source
　312 Detection optical signal output unit
　313 Pattern detection unit
　314 Disturbance generation unit
　315 Filter
　316 Radio transmission unit
　32 Sensor unit
　33 Optical fiber for sensing
　34 Buffer material
　40 Monitoring object
　50 Branching unit
　60 Analyzer
　P1, P2 Monitoring point
　CN connector
The scope of the claims
[Claim 1]
　A sensor unit for storing the sensing optical fiber,
　and a fixing unit for fixing the sensor unit to the object to be monitored,
　and a fiber connection part connectable to the sensing optical fiber to the optical fiber,
　said fiber connecting portion , An
　optical fiber sensing extension device that superimposes the detection result of the sensor unit on an optical signal transmitted by the optical fiber.
[Claim 2]

　The optical fiber sensing expansion device according to claim 1, 　wherein the optical fiber is an existing optical fiber .
[Claim 3]

　The optical fiber sensing according to claim 1 or 2, 　wherein the fiber connection unit detects a pattern corresponding to the monitored object based on the detection result of the sensor unit, and superimposes the detected pattern on the optical signal. Expansion device.
[Claim 4]

　The optical fiber sensing expansion device 　according to claim 3, wherein the fiber connection portion applies disturbance to the optical fiber according to the detected pattern .
[Claim 5]

　The optical fiber sensing expansion device according to any one of claims 1 to 4, 　wherein the fixing portion fixes a housing including the sensor portion to the monitored object .
[Claim 6]

　The optical fiber sensing expansion device according to any one of claims 1 to 5, 　wherein the sensing optical fiber is arranged in each of the three axial directions orthogonal to each other in the sensor unit .
[Claim 7]
　The fixing portion according
　to any one of claims 1 to 6 , wherein the sensor portion is fixed to the monitoring object with a cushioning material sandwiched between the sensing optical fiber and the monitoring object. The optical fiber sensing extension device described.
[Claim 8]
　The optical fiber is branched by a branch portion, and the
　fiber connection portion connects the sensing optical fiber to the line of the optical fiber branched by the branch portion,
　any one of claims 1 to 7. The optical fiber sensing extension device according to the section.
[Claim 9]
　A wavelength is assigned to each line of the optical fiber, and the
　fiber connection portion includes a filter for passing an optical signal having a wavelength assigned to the line of the optical fiber to which the optical fiber for sensing is connected.
　The optical fiber sensing extension device according to claim 8 , which transmits and receives an optical signal of the wavelength to and from a line .
[Claim 10]
　A wavelength is assigned to the optical fiber sensing expansion device, and the
　fiber connection portion includes a filter for passing an optical signal having a wavelength assigned to the optical fiber sensing expansion device, and connects the sensing optical fiber.
　The optical fiber sensing extension device according to claim 8, wherein an optical signal having the wavelength is transmitted to and received from the optical fiber line.
[Claim 11]
　An optical fiber,
　a sensor unit for storing a sensing optical fiber,
　a fixing unit for fixing the sensor unit to a monitoring object,
　a fiber connecting unit capable of connecting the sensing optical fiber to the optical fiber, and a
　detection unit. The
　fiber connection unit superimposes the detection result of the sensor unit on the optical signal transmitted by the optical fiber, and the
　detection unit is based on the detection result of the sensor unit superimposed on the optical signal. An
　optical fiber sensing system that detects a pattern according to the monitored object .
[Claim 12]

　The optical fiber sensing system according to claim 11, 　wherein the optical fiber is an existing optical fiber .
[Claim 13]

　The optical fiber sensing according to claim 11 or 12, 　wherein the fiber connection unit detects a pattern corresponding to the monitored object based on the detection result of the sensor unit, and superimposes the detected pattern on the optical signal. system.
[Claim 14]

　The optical fiber sensing system 　according to claim 13, wherein the fiber connection portion applies disturbance to the optical fiber according to the detected pattern .
[Claim 15]

　The optical fiber sensing system according to any one of claims 11 to 14, 　wherein the fixing portion fixes a housing including the sensor portion to the monitored object .
[Claim 16]

　The optical fiber sensing system according to any one of claims 11 to 15, 　wherein the sensing optical fiber is arranged in each of the three axial directions orthogonal to each other in the sensor unit .
[Claim 17]
　A cushioning material sandwiched between the sensing optical fiber and the monitored object is further provided, and the
　fixing portion has the cushioning material sandwiched between the sensing optical fiber and the monitored object.
　The optical fiber sensing system according to any one of claims 11 to 16 , wherein the sensor unit is fixed to the monitored object .
[Claim 18]
　Any one of claims 11 to 17, 　further
　comprising a branching portion for branching the optical fiber, the fiber connecting portion connecting the sensing optical fiber to the line of the optical fiber branched by the branching portion.
The optical fiber sensing system described in.
[Claim 19]
　A wavelength is assigned to each line of the optical fiber, and the
　fiber connection portion includes a filter for passing an optical signal having a wavelength assigned to the line of the optical fiber to which the optical fiber for sensing is connected.
　The optical fiber sensing system according to claim 18, wherein an optical signal of the wavelength is transmitted to and received from the line .
[Claim 20]
　A plurality of optical fiber sensing expansion devices including the sensor unit, the fixing unit, and the fiber connection unit are provided,
　and a wavelength is assigned to each optical fiber sensing expansion device, and the
　fiber connection unit owns the light. a filter for passing an optical signal of the wavelength assigned to the fiber sensing expansion device, transmit and receive optical signals of wavelength between lines of the optical fiber connected to the sensing optical fiber,
　according to claim 18 Fiber Optic Sensing System.